Earth compacting device



y 27, 1959 w. c. LATH ERS 3,446,123

EARTH COMPACTING DEVICE Filed Feb. 21, 1967 I N V ENTO 2. W/.4 mm? C. A r/mes wMirLwmw ATTQEN EY5 United States Patent U.S. Cl. 94-50 7 Claims ABSTRACT OF THE DISCLOSURE Sheeps-foot rotors are rotatably mounted in annular series on a skeletonized cylinder which is supported for rotation on its own axis. Each sheeps-foot rotor comprises a hub from which sheeps-foot legs radiate, the legs having faces converging to edges facing each other to squeeze out axially dirt which might otherwise be trapped between the legs. A stationary comb has teeth projecting at both sides of each annular series of rotors to engage and discharge such dirt. Rotatable sleeves coaxial with the rotors of one series are immediately proximate the paths of movement of the sheeps-foot ends of the legs of the staggered rotors of the next series, whereby to dislodge radially projecting earth.

BACKGROUND OF THE INVENTION The features stressed above are improvements upon the device shown in my prior Patent 3,269,285, granted Aug. 30, 1966. In that patent I used rotors having but four legs. I recognized that a greater number of legs would be desirable but it was felt that they might not clear themselves of sticky earth. In the instant device, I use five or six legs with sheeps-foot terminals and I assure clearance by the features specifically recited in the abstract of disclosure. They are all effective in clearing the device of earth when the soil which the rollers traverse is sticky and might otherwise impair the freedom of rotation of the individual rotors.

SUMMARY OF INVENTION It is particularly desirable to have each rotor provided with at least five, and preferably six, radial legs to perform the sheeps-foot function of compressing the soil traversed by the device. However, it has not heretofore been considered feasible to provide so many legs because of the tendency of some soils to pack between the legs when the angle between them is small. That tendency is obviated in the instant device by so designing the legs that they present sharp edges to each other, such edges being formed by surfaces which, in the instant device, are at an angle of 45 or less to a plane normal to the axis upon which the rotor turns. With the surfaces of consecutive legs at 90 or more with refernce to each other, the earth into which the legs penetrate tends to extrude itself from between the legs, being forced axially of the respective rotor to positions where the earth will either be dislodged or will project from the rotor to be scraped off by the comb teeth hereinafter mentioned. The result is that the rotors do not fill up with earth.

Clearing of the earth from between the legs of the sheeps-foot rotors is facilitated by the provision of station- 'ary comb teeth which project from the frame of the device to extend beside each rotor so that the rotor moves between two proximate teeth as the drum turns. Any protruding masses of earth are engaged by the comb teeth and caused to move outwardly from between the legs of the rotor. Some of the balls of earth will be dislodged completely by the comb teeth. In other cases, the earth may be caused to move radially from between the legs of the rotor. In the latter case, the masses of earth will encounter freely rotatable rolls which tend to eject them from the drum.

DESCRIPTION OF THE INVENTION In the drawings:

FIG. 1 is a view in side elevation of an earth compacting device embodying the invention, portions of the supporting frame being broken away.

FIG. 2 is a fragmentary plan view looking downwardly and forwardly on the drum mounted rotors of a device embodying the invention.

FIG. 3 is a fragmentary detail view taken in axial section through a portion of the drum and rotors of two annular series, parts being broken away.

FIG. 4 is an enlarged detail view in perspective of a six leg sheeps-foot rotor.

FIG. 5 is a view taken in cross section through two consecutive legs on the line 5-5 of FIG. 4.

Aside from the features mentioned above in the summary of invention, the device is essentially as shown in my former Patent 3,269,285. As in the device of the patent, there is a skeletonized drum 8 comprising side rings 10 supported by spokes 12 from a shaft 14 upon which the drum is bodily rotatable. The tie bolts 16 connect together the side members 10 and the intermediate rings 18. The rotors generally designated by reference character 20 (and separately illustrated in FIG. 4) are freely rotatable on tie bolts 16 between the rings 10, 18. The rotors are in staggered annular series. Where the rotors of any given series are absent between rings 18, the latter are spaced by sleeves 22.

In accordance with the invention, rollers 24 are mounted to turn freely on the spacers 22. So that they will not bind, the rollers 24 are slightly shorter than the spacing sleeves 22 and are big enough in their central openings 26 to turn freely about the sleeves. The external peripheries 28 of the rollers 24 are sufiiciently large so that as the sheeps-foot rotors 20 turn upon the respective tie bolts 16, the sheeps-foot treads 30 at the ends of their legs 32 pass in close proximity to the rollers 24.

Each of the rotors 20 includes a hub 34 having generally radial legs 32, which are not only integral with the hub but preferably merge with each other as shown in FIG. 4. The faces 40 of the several legs 32 converge toward the edges 38 and are desirable at no less than to each other as clearly appears in FIG. 5.

But for the wide angles between the faces 40 and convergence of such faces to form the edges 38, soil having and tendency to pack would lodge between sheeps-foot legs which are as close together as shown. However, 'by reason of the wide divergence of faces 40, the earth pushed toward the hub between the legs 32 tends to be extruded axially of the hub from between such legs.

If the earth still clings between the legs, the emergent portions thereof will be caught by the comb teeth 44. These are so mounted on the frame 46 as to lie quite closely beside the paths of movement of respective rotors. As the drum rotates on its shaft 14 and the respective rotors turn individually upon the spacing sleeves 24, the comb teeth will tend to dislodge the entrapped earth or to force it radially of the rotors. Any earth which projects radially beyond the tread of one of the rotors will encounter one of the freely rotatable rollers 24 which will complete the dislodgement of the clinging earth and cause it to fall to the ground.

What is claimed is:

1. In a device for tamping compactible material, said device including the combination of a rotatable drum, and sheeps-foot rotors mounted thereon for separate rotation and each comprising a hub having generally radial legs; the improvement which consists in providing the said legs in said combination with forwardly and rearwardly directed edges angularly spaced from correspond ing edges of adjacent legs and with side surfaces which are convergent toward said legs; said surfaces tending to extrude axially from between said legs material forced between said legs during use of the tampering device, the drum comprising spaced rings and tie rods extending axially of the drum and spanning the spaces between respective rings, the said rotors being in respective annular series in which therotors of one series are circumferentially staggered with respect to the rotors of the next series, the rotors of each series being mounted on alternate tie rods and the intervening tie rods having spacers between rings, and rollers mounted to turn about the spacers and disposed in positions proximate to the paths of the ends of respective tamping legs on said rotors.

2. A sheeps-foot rotor for tamping compactible material and comprising a rotatably mounted hub, tamping legs extending generally radially from the hub and in close circumferential proximity, said legs having forwardly and rearwardly directed edges close together adjacent the hub and angularly divergent radially from corresponding edges of adjacent legs, said legs further having faces converging obliquely toward said edges and adapted to extrude axially from between said legs material forced between said legs during use of the rotor.

3. A device for tamping compactible material, said device including in combination a series of rotors each of which comprises a rotatably mounted hub and generally radial sheeps-foot tamping legs, said legs having forwardly and rearwardly directed edges angularly spaced from like edges of adjacent legs and further having side surfaces convergent toward the respective edges and cooperating to extrude axially from between said legs material forced between the legs during use of the tamping device, and means upon which the respective rotor hubs are operatively mounted for independent rotation, said means comprising an axle shaft and a frame constituting means for positioning the shaft and having an element extending across the drum and provided with comb teeth between which the respective rotors move in proximity to the teeth during drum rotation on said shaft.

4. In a device for tamping compactible material said device including a plurality of sheeps-foot rotors mounted in annular series, and means supporting said rotors for orbital movement and for rotary movement upon their respective axes, each rotor comprising a hub having generally radial legs which are closely proximate to each other adjacent the respective hub; the improvement which consists in providing the said legs with forwardly and rearwardly directed edges which are immediately adjacent in the vicinity of the hub to the edges of successive legs of the same series and which diverge angularly from such last mentioned edges in a radially'outward direction from the hub, said legs having side surfaces convergent toward respective edges, the surfaces of successive legs tending to extrude axially the material which is forced between said legs during use of the tamping device.

5. A device for tamping compactible material according to claim 4 in which the said edges of respective legs merge with the edges of successive legs in the vicinity of the hub.

6. In a device for tamping compactible material, a shaft, hub means on the shaft from which spokes project radially, tie bolts in annular series about the shaft and connected with the spokes, sheeps-foot rotors mounted in annular series upon the tie bolts for orbital movement therewith about the axis of the shaft, each such rotor including a rotor hub also rotatable upon its respective tie bolt, each such rotor including a number of legs having portions radiating in immediate proximity to each other from the respective rotor hub, successive legs having opposed radially divergent edges forwardly and rearwardly directed and with side surfaces which are convergent toward said edges; the said surfaces of successive legs tending to extrude axially from between said legs material forced between said legs during use of the tamping device.

7. A tamping device according to claim 6 in which said tie bolt supports a plurality of circumferentially disposed series of sheets-foot rotors, with the rotors of respective series being staggered with respect to the rotors of adjacent series, the forward and rearward edges of the respective legs being disposed substantially in a plane normal to the axis of said shaft.

References Cited UNITED STATES PATENTS 2,579,839 12/1951 Le Tourneau 94-50 2,587,463 -2/ 1952 Guignard 94-50 3,269,285 8/1966 Lathers 94-50 3,318,211 5/1967 Grace 94-50 JACOB L. NACKENOFF, Primary Examiner.

US. Cl. X.R. 172-554 

